Ac losses of multifilament superconductors at frequencies between 1 and 500 Hz

A report is given of calorimetric measurements of the ac losses of a small superconducting coil wound from a filament superconductor designed for low ac losses (filament phi = 8 μ, number of filaments 1045, CuNi barriers). The coil was pulsed with a maximum dB/dt = 480 kG/s. Further the ac losses were measured, when the coil current consisted of a dc- and a super-imposed ac component with 1 less than or equal to f less than or equal to 500 Hz. The modification of the ac losses by the dc component of coil field and coil current was investigated. 3 figures